Immune reconstitution and severity of COVID-19 among hematopoietic cell transplant recipients.

Severe acute respiratory syndrome coronavirus 2 can lead to life-threatening coronavirus disease 2019 (COVID-19) infections in patients with hematologic malignancies, particularly among hematopoietic cell transplant (HCT) recipients. We describe two patients with COVID-19 during the pre-engraftment period after HCT and review previous reports of COVID-19 in HCT recipients. Because of significant mortality from COVID-19, primarily after allogeneic HCT, early, preemptive, and optimal directed therapy may improve outcomes and reduce the mortality rate but still needs to be established in clinical trials.